The present study was undertaken to reveal underlying mechanisms of apoptosis in neurons using clonal neuronal cells, ML-DmBG2-c2, derived from Drosophila larval central nervous system 1-(5-Isoquinolinesulfonyl)-2-methylpiperazine (H-7), a protein kinase inhibitor, induced cell death with typical features of apoptosis such as internucleosomal DNA fragmentation, nuclear condensation and apoptotic bodies in the cells. Though H-7 is known to inhibit cAMP-dependent protein kinase (PKA), protein kinase C (PKC), cGMP-dependent protein kinase (PKG), myosin light chain kinase (MLCK), and casein kinase I (CKI), specific inhibitors for these kinases such as H-89, calphostin C, ML-9, or CKI-7 did not induce apoptosis in the cells. Other kinases such as tyrosine kinase. PI3-kinase and Ca2+/CaM kinase II so far examined in the present study were interpreted not to be involved in the apoptotic cascade. Therefore, it is concluded that an H-7-sensitive substance(s) other than these kinases is responsible for the apoptosis in the neuronal cells. Caspase inhibitors prevented apoptosis in the cells treated with H-7. These results suggest that caspase(s) is involved downstream of the H-7-sensitive point in the cascade of the apoptosis.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1998

Recurrent excitation of motoneurons in the isolated spinal cord of newborn rats detected by whole-cell recording.

Motoneurons in the isolated spinal cord of newborn rats (1- to 6-day-old) were visualized using infrared videomicroscopy. Whole-cell recordings were performed from the neurons under observation. Stimulation of a sciatic nerve which adjoined ventral roots elicited postsynaptic currents (PSCs) in 28 out of 88 motoneurons. When membrane potentials were changed, some PSCs reversed at around -70 mV, which was compatible with the chloride equilibrium potential calculated. Thus, they were considered to be recurrent inhibitory, namely Renshaw inhibition. On the other hand, we detected PSCs which reversed at +3.3 mV on average. They were interpreted as excitatory based on the level of the reversal potential which was similar to that of orthodromic excitatory PSCs. To determine the origin of the antidromic excitatory inputs, the effect of d-tubocurarine (10 microM) on the PSCs was examined. In three out of five motoneurons, the excitatory currents were eliminated. Therefore, it was concluded that the excitatory inputs, if not all, are mediated via the axon collaterals. Furthermore, it was found that the locations of motoneurons receiving the recurrent inhibitory and the excitatory PSCs were different in the spinal cord.

Animals↗

PubMed1998

[Memory function in aging and Parkinson's disease--an event-related potential study].

The N400 of event-related potentials (ERPs) was recorded in 17 healthy young subjects (mean age 24.4 years), 14 healthy old subjects (healthy control subjects, mean age 62.7 years), and 21 patients with nondemented Parkinson's disease (PD, mean age, 63.8 years) as they listened to words or nonwords. Some words were repeated immediately after the initial presentation (2 sec), while others were repeated after 5 intervening words (12 sec) or after 2 to 4 minutes. The subjects were required to respond to occasional nonwords. Rey's auditory verbal learning test(AVLT) was also performed. The mean N400 amplitude was smaller in patients with PD than in either healthy group, but there was no difference between the two healthy groups. In the young subjects, N400 was attenuated for repeated words, and the attenuation was more pronounced for immediate than for delayed repetitions. N400 attenuation in the old subjects was more markedly reduced as the interval between the 1st and 2nd presentation increased than in the young subjects. In PD patients, attenuation was noted only for immediate repetition. Free recall by the old subjects was impaired relative to the young subjects throughout the AVLT trials, and was even more impaired in patients with PD. In addition, the number of free recalls increased less with the number of trials in patients with PD than in the old subjects. These results may indicate that episodic memory declines with advancing age, and declines even more in patients with PD. In addition, the ability to transform information form short-term memory to long-term memory appear to be impaired in patients with PD.

Adult↗

PubMed1998

[The effect of interviewer distance on eyeblinks and heart rates of interviewee].

The purpose of the present study was to investigate the effect of interviewer distance on interviewee eyeblinks and heart rates. The interviewer was a 22 year-old woman, and 21 undergraduates, eight men and 13 women, participated in the study as interviewees. Interviews were conducted under three distance conditions: close (0.8 m), middle (2.0 m), and distant (4.0 m). A polygraph recorded the interviewee's eyeblinks and heart rates during the interview. After the interview, the interviewee rated his/her own psychological state during the interview, and reported impressions of the interviewer. Results showed that interviewees blinked more frequently in the close condition than the other conditions. No significant effect was found on heart rate. Interviewees rated their psychological state as more negative in the close condition, but impression to the interviewer remained the same across the conditions. These results indicated that eyeblink is a useful physiological index of effects that interpersonal situations have.

Adult↗

PubMed1998

Relationship of xenogeneic microchimerism to graft outcome in hamster-to-rat lung xenotransplantation.

BACKGROUND: In spite of the progress in allogeneic microchimerism research, few reports have dealt with the biologic relevance of xenogeneic microchimerism after organ xenotransplantation. These experiments were designed to analyze the development of xenogeneic microchimerism and its relationship to graft outcome in hamster-to-rat lung xenotransplantation. METHODS: Golden Syrian hamsters were the donors and Lewis rats the recipients of xenogeneic lung transplantation. Animals were divided into three groups: group 1 were untreated; group 2 received cyclophosphamide (10 mg/kg/day for 6 days) and a short course of FK506 (2 mg/kg/day for 8 days); and group 3 were treated with cyclophosphamide and a long course of FK506 (2 mg/kg/day for 8 days, 1 mg/kg/day for 23 days, and then 0.5 mg/kg/day continuously). Xenogeneic microchimerisms were evaluated by use of polymerase chain reaction with primers specific for the hamster hypoxanthine phosphoribosyl-transferase gene. RESULTS: The median graft survival times for groups 1, 2, and 3 were 3 days (n = 6), 22 days (n = 7), and 96.5 days (n = 6), respectively. In groups 1 and 2, the incidence of microchimerisms declined in parallel with the progression of rejection. In group 3, it changed dynamically, initially declining, then progressively increasing and finally disappearing. CONCLUSIONS: In the short-term graft survivors, xenogeneic microchimerism in the peripheral blood was closely related to graft outcome. However, it showed dynamic changes and finally disappeared in long-term graft survivors, and the incidence of microchimerism at a single time point did not reflect the donor-recipient immunologic status.

Animals↗

PubMed1998

[Multicentric Castleman's disease with lymphoid interstitial pneumonia and polyneuropathy].

A 51-year-old woman was admitted to a local hospital because of pneumonia, and received a diagnosis of cervical lymphadenopathy, anemia, and hyperimmunoglobulinemia with suspected multicentric Castleman's disease (MCD). At the age of 53 she was transferred to our hospital because of numbness and muscle weakness. Polyclonal hyperimmunoglobulinemia was observed, and biopsy specimens of lymph node tissue revealed infiltration of plasma cells in the interfollicular areas, thus leading to a diagnosis of MCD. A chest computed tomography scan revealed diffuse nodular shadows in all lung fields, and a transbronchial lung biopsy disclosed infiltration of plasma cells in the alveolar septa. Together, these findings indicated lymphoid interstitial pneumonia (LIP). Polyneuropathy was diagnosed by neurological examination and nerve conduction studies. Treatment with prednisolone and cyclophosphamide was ineffective against LIP probably because the patient had coexising pulmonary fibrosis. Since pulmonary complications of MCD determine its prognosis, their early detection and treatment are essential.

Castleman Disease↗

PubMed1998

Effect of the angiotensin-converting enzyme inhibitor enalapril on post-transplant erythrocytosis.

Post-transplant erythrocytosis (PTE) is increasingly recognized as a complication of kidney transplantation. In this study we report the effect of the angiotesin-converting enzyme (ACE) inhibitor enalapril on hematocrit (Ht) and erythropoietin in four patients with PTE. Four renal allograft recipients with Ht greater than 51% were studied. Treatment was initiated with enalapril administered orally at a dose of 2.5 mg/day. All the patients had an increase of hemoglobin (Hb) (17.7 +/- 0.64 g/dl), Ht (54.5 +/- 1.29%) and red blood cell count (RBC) (584 +/- 19.2 x 10(4)/microliter). All patients responded to enalapril in 8 weeks with a significant decrease of Hb, Ht, and RBC. In one patient, the downward trend was more rapid and sustained, and treatment had to be discontinued to prevent the development of anemia. Serum erythropoietin showed normal in all four patients and remained unchanged during the study, even after discontinuation of enalapril treatment. Serum creatinine remained relatively stable throughout the study. These results suggest that PTE may not be dependent upon circulating erythropoietin and that enalapril treatment may be an effective treatment of PTE without renal dysfunction.

Adult↗

PubMed1998

[Efficacy of granisetron in the prevention of emesis induced by conditioning chemotherapy for allogeneic bone marrow transplantation].

We conducted this study to compare granisetron, 5-HT3 antagonist, with conventional antiemetics in the prophylaxis of emesis induced by conditioning chemotherapy for allogeneic bone marrow transplantation in 41 patients. The conditioning chemotherapy regimen included either cytosine arabinoside 2 g/m2 x 4 and cyclophosphamide 60 mg/kg x 2 (CA, CY), or busulfan 4 mg/kg x 4 and cyclophosphamide 60 mg/kg x 2 (BU, CY). In CA and CY regimen, the clinical effective rate with granisetron against emesis was 94.1% on the 1st day, compared with 7.6% in the control group. On day 2 and 3, the effective rate with granisetron was 58.8% and 23.5%, respectively, compared with 0% in the control group. In the BU and CY regimen, control of emesis with granisetron on day 5 and 6 was 66.7%, against 20.0% in the control group. Based on these data, we concluded granisetron is superior to conventional antiemetics in the prophylaxis of emesis induced by conditioning for allogeneic bone marrow transplantation.

Adolescent↗

PubMed1997

Phosphorylation of the immunosuppressant FK506-binding protein FKBP52 by casein kinase II: regulation of HSP90-binding activity of FKBP52.

FKBP52 (HSP56, p59, HBI) is the 59-kDa immunosuppressant FK506-binding protein and has peptidyl prolyl isomerase as well as a chaperone-like activity in vitro. FKBP52 associates with the heat shock protein HSP90 and is included in the steroid hormone receptor complexes in vivo. FKBP52 possesses a well conserved phosphorylation site for casein kinase II (CK2) that was previously shown to be associated with HSP90. Here we examined whether FKBP52 is phosphorylated by CK2 both in vivo and in vitro. Recombinant rabbit FKBP52 was phosphorylated by purified CK2. We expressed and purified deletion mutants of FKBP52 to determine the site(s) phosphorylated by CK2. Thr-143 in the hinge I region was identified as the major phosphorylation site for CK2. A synthetic peptide corresponding to this region was phosphorylated by CK2, and the peptide competitively inhibited the phosphorylation of other substrates by CK2. The [32P]phosphate labeling of FKBP52-expressing cells revealed that the same site is also phosphorylated in vivo. FK506 binding to FKBP52 did not affect the phosphorylation by CK2 and, conversely, the FK506-binding activity of FKBP52 was not affected by the phosphorylation. Most importantly, CK2-phosphorylated FKBP52 did not bind to HSP90. These results indicate that CK2 phosphorylates FKBP52 both in vitro and in vivo and thus may regulate the protein composition of chaperone-containing complexes such as those of steroid receptors and certain protein kinases.

Amino Acid Sequence↗

PubMed1997

Cdc37 is a molecular chaperone with specific functions in signal transduction.

Cdc37 is required for cyclin-dependent kinase activation and is genetically linked with the activity of several other kinases, including oncogenic v-Src, casein kinase II, MPS-1 kinase, and sevenless. Strikingly, many pathways involving Cdc37 also involve the protein chaperone Hsp90. The identification of Cdc37 as the 50-kD protein in several Hsp90-kinase complexes, together with other data, led to the recent suggestion that Cdc37 is a kinase-targeting "subunit" of Hsp90. We directly examined the effect of Cdc37 on Hsp90 functions. Rather than simply acting as an accessory factor for Hsp90, Cdc37 is itself a protein chaperone with properties remarkably similar to those of Hsp90. In vitro, Cdc37 maintains denatured beta-galactosidase in an activation-competent state without reactivating it and stabilizes mature, but unstable, casein kinase II. In vivo, Cdc37 overexpression can compensate for decreased Hsp90 function, but the proteins are not interchangeable. Cdc37 can compensate for Hsp90 in maintaining the activity of v-Src kinase but does not maintain the activity of the glucocorticoid receptor. Thus, the very similar chaperone activities of the two proteins, uncovered through in vitro analysis, diverge in vivo in specific signal transduction pathways.

Cell Cycle Proteins↗